Table 3.

Brief summary of the constructions, crosslinking mechanisms, properties, and biomedical applications of NSHs

Constructions	Hydrogel systems	Crosslinking mechanisms	Properties	Biomedical applications	Ref.
By increasing crosslinking density	HA‐norbornene, HA‐ methylphenyltetrazine	IEDDA reaction	Non‐swelling, transparent, cytocompatible biodegradable	Not‐involved	[13b]
	HB‐PEGDA, HA‐SH, colloidal photonic crystal	Michael addition reaction	Non‐swelling, robust, photonic, biocompatible	Bio‐optical application	[157]
	CS, PAM, antibiotics	Double covalent network	Anti‐swelling, robust, adhesive, antibacterial	Intraoral wound healing	[219]
	PVA, TA	Multiple H‐ bonding	Hierarchically anisotropic, super‐strong, nonswellable, cytocompatible	Not specific	[13d]
	PVA, DMSO	H‐bonding	Anti‐swelling, strong, wet adhesive	Not specific	[13c]
	PEGDA, TA	H‐bonding	Non‐swelling, tough, notch insensitive, self‐healing, tailorable topography, wet adhesion, on‐demand detachment, biocompatible	Underwater wound sealant	[227]
	P(AA‐co‐LMA), CTAB	Hydrophobic association, electrostatic interaction, H‐bonding	Tough, self‐recovery, anti‐swelling, conductive, wet adhesive, strain‐sensitive	Underwater sensor	[180]
	SA, P(AM‐co‐AA), Fe3+	Dual ionic crosslinking	Robust, tough, fatigue‐resistant, self‐recovery, pH‐triggered healing, shape memory, anti‐swelling, 3D‐printable	Not specific	[183]
	P(AA‐co‐DMAA), Al(OH)3	Metal nanoparticle coordination	Nonswellable, ultra‐strong, superoleophobic	Not involved	[13a]
	PSBVI, graphene	Cation‐π interaction	Conductive, bioadhesive, non‐swelling, high conformability, biocompatible	Bioelectronics	[243a]
	GelMA, acryloyl‐β‐CD, β‐CD‐rGO	Covalent bonding, host‐guest complexation	Conductive, non‐swelling, biocompatible, photothermal antibacterial, osteogenic	Bone defect repair	[231]
	‐CHO‐capped tetra‐arm PEG, ‐ONH2‐capped PEG‐UPy‐PEG	Chemical and micelle physical dual crosslinking	Injectable, strong, tough, stable, non‐swelling, an‐fatigue, tissue‐adhesive, cytocompatible	Not specific	[195b]
	pHEMA, alginate, Fe3+	Interpenetrating covalently and ionically crosslinked networks	Non‐swelling, stiff, tough, cytocompatible	Not involved	[203]
	Cellulose, PAM, aniline	H‐bonding, covalent bonding	Conductive, tough, stretchable, elastic, non‐swelling, biocompatible, underwater strain‐sensitive	Strain sensor	[47]
By regulating polymer‐water interaction	P(AA‐co‐MEA), nucleobase pairs, DMSO‐water binary solvent	H‐bonding	Non‐swelling, anti‐freezing, wet adhesive, tough, mechanically stable	Sweaty skin sensor	[144]
	P(AA‐co‐MEA), CMC, Al3+, DMSO‐water binary solvent	Covalent bonding, ionic crosslinking, H‐bonding	Anti‐swelling, anti‐freezing, moisturizing retention, underwater/oil strain‐sensitive, optically adjustable, flexible	Multipurpose biosensor	[13f]
	Hydrogel components: P(HEA‐co‐DMA), clay nanosheets, Organogel components: PBA	Covalent bonding	Stretchable, tough, enduring anti‐swelling, low dehydration	Not specific	[206b]
	Hydrogel layer: P(AA‐co‐HEA)/MXene, Lipogel layer: hydrophobic lipid gel	Covalent bonding	Anti‐swelling, anti‐hydration, long‐term ultra‐stable, underwater mechanosensitive	Underwater mechanosensing	[210b]
By including thermo‐responsive polymer	2‐arm thiol‐ terminated Pluronic l‐64 PEG, 3‐arm alkyne terminated PEG	Thiol‐yne click reaction	Non‐swelling, cytocompatible	Soft tissue scaffold	[145a]
	Di‐acrylated Pluronic F127	Covalent bonding	Non‐swelling, autoclavable, degradation‐resistant	Not specific	[145b]
	HA‐MA, Pluronic F127‐bis‐acryloyloxy acetate	Covalent bonding	Anti‐swelling, injectable, wet adhesion, biocompatible	Hemostasis and wound sealing	[13h]